This puff pancake is yeasty and melt-in-your-mouth good!
Preheat oven to 425 degrees F (218 C). Place the butter in a glass 13x9-inch baking dish and put in the oven to melt. Keep an eye on it so it doesn't burn! Remove from oven once melted.
Place the remaining ingredients except for the blueberries in a blender. Blend for 1 minute, making sure everything is well combined.
Pour the batter over the melted butter in the baking dish. Sprinkle the blueberries evenly on top if desired.
Bake in preheated oven for 15-20, or until the edges are deep golden brown and the pancake has puffed up. Serve with extra butter and a drizzle of maple syrup if desired.